X-ray tube



Patented pr. 10, 17934 PATENT OFFICE X-RAY TUBE Heinrich Halberstadt, Hamburg, Germany, as-

signor to C. H. F. Mller, Aktiengesellschaft,

Hamburg, Germany Application May 20, 1931, Serial No. 538,823 In Germany May 22, 1930 4 Claims.

In the use of soft X-rays for therapeutic purposes it has been found to be advantageous to subject that part of the body to be treated to the action of heat rays simultaneously with the radiation by X-rays. These heat rays are produced for example by a heater arranged concentrically around the radiation window of the X- ray tube. Such a'heater has the disadvantage of necessitating separate electric conductors for supplying heating current and of requiring a separate source of voltage for the purpose. In addition, there is the risk that the radiation window of the "l-ray tube which consists of comparatively readily fusible glass may be heated by the said additional heater to the temperature of softening which may bring about the entire destruction of the tube. The present invention relates to an electron discharge tube for producing X-rays, which is so constructed that the disadvantages noted above are obviated. According to this invention, instead or" utilizing the heat radiation of a separate heater, the thermal energy produced by the incandescent cathode in the X-ray tube itself is made available. In order to cause the said thermal energy to act on that part of the body which is to be treated, it is concentrated by means of a hollow mirror or reflector arranged around the radiation window and is reflected in the desired manner on to the diseased part or" the body to be treated. Preferably, the hollow rem flector is made of a metal having a satisfactory reflecting capacity for long-wave thermal radiation. It is also possible to provide an arrangement comprising a plurality of reflectors of different radii of curvature, or of reflectors having a variable radius of curvature adjustable at will according to whether a larger or a smaller field should be covered by thermal rays. 'Ihe radius of curvature can be varied, for example, by means of a hinge adapted to open or close the hollow reflector to a greater extent. The use of such hollow reflectors has the additional advantage over a separate heater, in that the radiation window is not exposed to a detrimental heating, as

the thermal energy is concentrated outside the tube on the hollow reiiector. As this hollow reilector has a satisfactory reflective capacity for heat rays, it cannot become heated strongly so that the radiation window remains substantially unaffected.

In order that the invention may be clearly un derstood and readily carried into effect, preferred embodiments of the invention are illustrated in the accompanying drawing. In Fig. 1 of the drawing is shown a discharge tube for producing soft X-rays of a known construction and including a grounded anode and a reflector. Fig. 2 illustrates a modication comprising an adjustable reector. l

Referring to the Fig. l, a tube 1 has her- 60 metically sealed to it the backbone of an anode 2, the inner conical surface 2a of which constitutes the target surface for the impinging cathode rays from an incandescent cathode 3. f Long-wave Y-rays pass from this point through d a radiation window 4 made, for example, of Lindemannglass. The anode has iixed around it a hollow reflector 5 which serves to concentrate the heat rays emitted by the incandescent cathode and reflects them on to the desired part of the 7U body of the person to be treated. This has the additional advantage over a separate heater, that the radiation window is not exposed to detrimental or destructive heating.

As shown in Fig. 2, the area upon which the heat rays from the cathode are concentrated may be varied by employing a reflector 5 having ad.- justable portions 6 hinged as indicated at 'I whereby the reflected rays may be concentrated to a greater or less extent as desired depending upon the positions of said adjustable portions 6 of the reflector.

W hat I claim is:

l. An evacuated container consisting of an insulating portion and a hollow metal member sealed thereto, said member serving as an X-ray `enfiitting-electrode, a heat-radiating incandescent cathode within said member, a vacuum-tight window closing said metal member at the side opposite to said insulating wall portion, through which window pass heat rays produced by said cathode and a beam of X-rays emitted by a portion of the inner surface of said hollow member located adjacent to said cathode, a hollow reiiector secured to said metal member and in line herewith, said reflector receiving and reiiecting the heat rays emitted by said cathode so as to concentrate these rays at a point situated in said beam of X-rays.

2. A discharge tube for producing X-rays having an enclosing envelope, part of which consists of metal and serves as an anode and a heatra diating incandescent cathode mounted in said envelope, the wall of the tube being provided with4 V a window for transmitting the desired beam of X-rays and the heat rays emitted by the cathode, a tub-shaped hollow reflector arranged in front of the window outside of said envelope in coaxial relation. with the beam of X-rays, said reflector serving to direct the heat rays produced by the il@ incandescent cathode through the opening of the reector opposite to said Window.

3. A discharge tube for producing X-rays having an enclosing envelope, part of which consists 5 of metal and serves as an anode and a heat-radiating incandescent cathode mounted in said envelope, the Wall of said envelope having a Windovv through which pass the Xerays emitted by said anode and also the heat rays produced byV i0 said cathode, and a hollow reector secured to the tube for reflecting the heat rays, the said reiector being adjustable to Vary the radius of its curva-A ture.

4. A discharge tube for producing X-rays hav- HEINRICH HALBERSTADT. 

